MOOEE — ABNORMAL SECONDAEY DEPOSITS. 



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The Lias in this curious section is most regularly bedclecl, and is 

 seen by reference to the diagram to occupy the centre of a small 

 ^ trough, into which its beds are 



compressed, with the Ehaetic "White 

 Lias asregularly underlying it. The 

 Avicula-contorta series below was 

 largely opened ; and I have never 

 had the pleasure of seeing any 

 other section to be compared Avith 

 it. The Keuper Marls and rocks 

 of the New Red Sandstone were 

 met with at the southern end of 

 the cutting ; and all were abruptly 

 cut oiF at a short distance to the 

 north by the Pennant rocks of the 

 Coal-measures, through which the 

 railway is afterwards continuous 

 to Mangotsfield. 



Although the present conforma- 

 tion of these beds is due to sub- 

 sequent disturbance, the peculiar 

 thickening of the Avicula-contorta 

 series below the "White Lias to the 

 south would lead me to suppose 

 that theymust have been deposited 

 on an uneven sea-bottom. 



At the base of the Lias in this 

 cutting there are thin representa- 

 tives of the Osfrea-liassica beds, 

 but without any trace of the In- 

 sect and Crustacean beds as in the 

 section at Camel (p. 462). The 

 " White Lias " which follows is re- 

 duced to a few beds of less than 

 four feet in thickness. 



The surface of the laminated 

 clay (2 h) is often entirely covered 

 by Cytliere Uassica, the specimens 

 being generally so uniformly ar- 

 ranged lengthwise as to show the 

 direction of the current of the 

 water by which they were last 

 washed. 



Large coprolites in the bed 2/ 

 led me to look carefully for rep- 

 tilian remains; and although it 

 was not so rich as was expected, 

 I obtained from it scattered ver- 

 tebroB and a large humerus of FJc- 

 siosaurus rugosus ? ; and this bed is noteworthy also from my being 



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